Boundary check for children creating of PatriciaTriePolicy.

Bug: 10537529
Change-Id: I0cd8b6de230795498395ca08789ccc1c74780f2c

native/jni/src/suggest/policyimpl/dictionary/patricia_trie_policy.cpp

@@ -31,9 +31,21 @@ void PatriciaTriePolicy::createAndGetAllChildNodes(const DicNode *const dicNode,
         return;
     }
     int nextPos = dicNode->getChildrenPos();
+    if (nextPos < 0 || nextPos >= mDictBufferSize) {
+        AKLOGE("Children PtNode array position is invalid. pos: %d, dict size: %d",
+                nextPos, mDictBufferSize);
+        ASSERT(false);
+        return;
+    }
     const int childCount = PatriciaTrieReadingUtils::getPtNodeArraySizeAndAdvancePosition(
             mDictRoot, &nextPos);
     for (int i = 0; i < childCount; i++) {
+        if (nextPos < 0 || nextPos >= mDictBufferSize) {
+            AKLOGE("Child PtNode position is invalid. pos: %d, dict size: %d, childCount: %d / %d",
+                    nextPos, mDictBufferSize, i, childCount);
+            ASSERT(false);
+            return;
+        }
         nextPos = createAndGetLeavingChildNode(dicNode, nextPos, childDicNodes);
     }
 }

native/jni/src/suggest/policyimpl/dictionary/patricia_trie_policy.h

@@ -36,6 +36,7 @@ class PatriciaTriePolicy : public DictionaryStructureWithBufferPolicy {
     PatriciaTriePolicy(const MmappedBuffer *const buffer)
             : mBuffer(buffer), mHeaderPolicy(mBuffer->getBuffer(), buffer->getBufferSize()),
               mDictRoot(mBuffer->getBuffer() + mHeaderPolicy.getSize()),
+              mDictBufferSize(mBuffer->getBufferSize() - mHeaderPolicy.getSize()),
               mBigramListPolicy(mDictRoot), mShortcutListPolicy(mDictRoot) {}
 
     ~PatriciaTriePolicy() {
@@ -118,6 +119,7 @@ class PatriciaTriePolicy : public DictionaryStructureWithBufferPolicy {
     const MmappedBuffer *const mBuffer;
     const HeaderPolicy mHeaderPolicy;
     const uint8_t *const mDictRoot;
+    const int mDictBufferSize;
     const BigramListPolicy mBigramListPolicy;
     const ShortcutListPolicy mShortcutListPolicy;